I mean, from the point of view of comparing the "usefulness" of a unit.
It is quite problematic not to lose Trogols when clearing the map, especially at the beginning of the game, while Gremlins, especially with a hero who has a slowing ability, are very effective.
Mr. Livuel did not take into account another (practical) point when comparing the Tower and the Dungeon:
at 200% difficulty level, the Tower with its Gremlins (upgraded) and Gargoyles, and some golems, can clear a significant part of its territory (archers + defense) with almost no losses (if Grand Elves don't happen to be near the wood mine). That is, building a Tower is not an easy task, but it is feasible even with a bad spawn... but for the Dungeon, in order to build Outposts, you need to have ALL the resources, even though they are few (1 each), and without archers (and without upgrading Harpies, which is also not easy) it is very difficult to do this without losses at the beginning of the game... freebies are unpredictable.
I think that the positional advantage is with the Tower. Fewer losses and clearing the map happens earlier